Weight lifting machines which employ a stack of individual weights, one or more of which can be "ganged" together to provide successively greater resistance, are common and well-known for physical fitness purposes. One disadvantage of these machines is their bulk and overall weight arising, of course, from the heavy stack (and sometimes stacks) of individual, graduated weights which they incorporate. With this in mind, some have tried substituting various combinations of springs and linkages, often coupled with gauges, for the weight stacks in order to reduce the bulk and weight of the machines concerned. But these substitutions seem never to have "caught on", as it were, perhaps because they in effect eliminate the psychological motivation that a physically large, heavy stack of weights provides a person who confronts their lifting. One wants a "large mass" to move as he lifts and the greater and bulkier the mass he is able to displace, the greater the satisfaction he obtains from the effort required. Hence the primary object of the present invention is a reduction in the bulk of current weight lifting machines without at the same time impairing the psychological motivation and satisfaction they provide.